A gas sensor device that measures physical quantities such as a moisture concentration of gas is used in various technical fields. In order to comply with exhaust gas regulations and to reduce fuel consumption, for example, physical quantities such as humidity, pressure, and temperature of intake air are measured in internal combustion engines for automobiles, and the measured physical quantities allow determination on an optimal amount of fuel consumption and time of ignition. Furthermore, in order to comply with increasingly tight exhaust gas regulations, it is required to measure physical quantities of gas with high accuracy so as to optimally drive internal combustion engines.
As an example of such a gas sensor device, JP 2011-137679 A (PTL 1) discloses a gas sensor device that includes a substrate having a hollow portion; a thin film support including a plurality of insulating layers laminated in the hollow portion; and first and second heaters sandwiched by the insulating layers of the thin film support. In this gas sensor device, the second heater is disposed around the first heater, and the first heater is controlled to be heated to a temperature higher than that of the second heater. Based on a radiation amount of the first heater, physical quantities such as humidity of gas are measured. Furthermore, in order to reduce measuring errors caused by changes in radiation amount of the first heater caused by temperature changes in ambient gas, the second heater is configured to maintain an ambient temperature of the first heater at a predetermined temperature so as to allow highly accurate measurement.